1. Feature Of The Week: Conical-Scan Polarization-Sensitive Optical Coherence Tomography (CS-PS-OCT)

    We report on a new articular cartilage imaging technique with potential for clinical arthroscopic use, by supplementing the variable-incidence-angle polarization-sensitive optical coherence tomography method (VIA-PS-OCT) previously developed by us with a conical beam scan protocol. In the protocol, the beam is scanned such that the k-vector sweeps out a conical surface whose apex is chosen, for convenience, to lie at the tissue surface. In the implementation reported here we achieve this by mounting the sample on a motorized rotation stage with the sample surface roughly parallel to the stage rotating plane (i.e. normal to the stage rotation axis). The stage is mounted and tilted at a certain angle typically 45o with respect to the laser illumination beam direction. Conical scan PS-OCT (CS-PS-OCT) imaging is then obtained by acquiring successive A-scans over rotation spans of 0-360 degrees at an interval of 1 degree. During imaging the illumination beam is fixed and intersects the stage rotation axis at a fixed measurement point on the sample surface. Therefore, the azimuthal angle between the beam and the tissue normal varies continuously and a polar B-scan of depth-resolved retardance is plotted.

    The technique is validated on bovine tendon by comparing experimental data with simulated data generated using the extended Jones matrix calculus. A unique capability of this new optical technique is that it can locate the “brushing direction” of collagen fibers in articular cartilage, which is structural information that extends beyond established methods such as split-line photography or birefringent fast-axis measurement in that it is uniquely defined over the full azimuthal-angle range of (-π, +π).

    The technique could facilitate the translation of the VIA-PS-OCT technique to the clinic by simplifying the requirements for the beam delivery probe, e.g. launching a low numerical aperture (NA) beam into a high NA objective lens.

    The mapping of this direction over the cartilage surface may offer insights into the optimal design of tissue-engineering scaffolds for cartilage repair, which are growing in sophistication through the use of additive manufacturing techniques. There is also an increasing interest in determining the regional structure of collagen fibers in cartilage in order to improve the accuracy of mechanical models of the tissue. New insights from CS-PS-OCT may then be of use in such studies.

    For more information see recent Article. Courtesy Zenghai Lu and Stephen Matcher from the University of Sheffield. To share this article click Here.
  2. Recent Articles From Around The Web

    1. Intricacies in the analysis and interpretation of optical coherence tomography findings

      Intricacies in the analysis and interpretation of optical coherence tomography findings

      The assessment of arterial wall healing following DES implantation with the use of optical coherence tomography (OCT) has become a standard in the systematic evaluation of coronary stents. As a result, the number of scientific manuscripts on stents and OCT has proliferated, and stent characteristics including strut coverage and malapposition are reported based on their association with stent thrombosis in observational studies1. In this issue of EuroIntervention, Kim and colleagues2 present the results of a randomised comparison between new-generation biodegradable biolimus-eluting stents… 

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    2. The University of Illinois at Urbana-Champaign Announces Illinois Proof-of-Concept Program Award Recipients

      The University of Illinois at Urbana-Champaign Announces Illinois Proof-of-Concept Program Award Recipients

      The Office of Technology Management (OTM) is proud to announce the 2014 awardees of the Illinois Proof-of-Concept (I-POC) Fund. I-POC enables development of projects that demonstrate an innovation’s market viability to potential investors and partners. Stephen Boppart , from the Beckman Institute for Advanced Science and Technology and the College of Engineering, for his Quantitative Pneumatic Otoscope , which uses optical coherence tomography (OCT) to visualize middle ear contents

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    3. Subfoveal Choroidal Thickness in Patients with Chronic Heart Failure Analyzed by Spectral-Domain Optical Coherence Tomography

      Subfoveal Choroidal Thickness in Patients with Chronic Heart Failure Analyzed by Spectral-Domain Optical Coherence Tomography

      Purpose : To evaluate the subfoveal choroidal thickness (SFCT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in eyes of chronic heart failure (CHF) patients. Methods : Fifty-six patients with CHF and 56 age- and gender-matched healthy individuals were enrolled. The SFCT was measured by EDI-OCT. The ejection fraction of left ventricle (EFLV), age, intraocular pressure (IOP), axial length (AL), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured. Results : Mean SFCT was 181.2 ± 80.23 μm in the study group and 283.6 ± 52.4 μm in the control group ( p  = 0.000). There was ...

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    4. Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

      Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

      We demonstrate an extended-imaging-range anterior-segment optical coherence tomography (eAS-OCT) system for the biometric assessment of full AS in human eye. This newly developed eAS-OCT operating at 1340-nm wavelength band is simultaneously capable of an imaging speed of 120 kHz A-line scan rate, an axial resolution of 7.2 μ m, and an extended imaging range of up to 16 mm in air. Imaging results from three healthy subjects and one subject with a narrow-angle demonstrate the instrument’s utility. With this system, it can provide anatomical dimensions of AS, including central corneal thickness, anterior chamber width, anterior chamber depth, crystalline lens ...

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      Mentions: Ruikang K. Wang
    5. Agreement of Retinal Nerve Fiber Layer Defect Location Between Red-Free Fundus Photography and Cirrus HD-OCT Maps

      Agreement of Retinal Nerve Fiber Layer Defect Location Between Red-Free Fundus Photography and Cirrus HD-OCT Maps

      Purpose : To investigate the agreement of angular locations of retinal nerve fiber layer (RNFL) defect margins in glaucomatous eyes by using red-free fundus photographs and Cirrus high-definition optical coherence tomography (OCT) RNFL deviation and thickness maps. Methods : We examined 380 RNFL defects that showed clear margins in red-free fundus photographs. The OCT deviation and thickness maps were overlaid on the corresponding red-free fundus photographs. A reference line was drawn between the disc center and the macular center. Lines were also drawn between the optic disc center and the point where the RNFL defect margins crossed the OCT scan circle. The ...

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    6. Interexaminer Reproducibility of Optical Coherence Tomography for Measuring the Tear Film Meniscus

      Interexaminer Reproducibility of Optical Coherence Tomography for Measuring the Tear Film Meniscus

      Purpose : New optical coherence tomography (OCT) devices with anterior segment module are able to measure the tear meniscus height (TMH) and tear meniscus area (TMA). Since the borders of the area and the height are to be marked by an examiner, the measurements are prone to be subjective. Herein, we aimed to evaluate the interexaminer reproducibility of the tear meniscus measurements with OCT. Materials and Methods : In this prospective cross-sectional study, both eyes of 300 consecutive patients with and without dry eye were studied. Following routine ophthalmologic examination, tear-film OCT images were obtained. Two examiners, who were unaware of the ...

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    7. Monitor Corneal Epithelial Healing Under Bandage Contact Lens Using Ultrahigh-Resolution Optical Coherence Tomography After Pterygium Surgery

      Monitor Corneal Epithelial Healing Under Bandage Contact Lens Using Ultrahigh-Resolution Optical Coherence Tomography After Pterygium Surgery

      Objective: To monitor corneal epithelial healing under bandage contact lens (BCL) using ultrahigh-resolution optical coherence tomography (UHR-OCT) after pterygium surgery. Methods: Thirty-nine eyes of 39 patients undergoing pterygium excision and conjunctival autografting were randomly allocated into 2 groups: 20 eyes were covered with silicone hydrogel BCLs at the end of surgery and 19 eyes served as a control. Ultrahigh-resolution optical coherence tomography scans of the cornea were performed sequentially at 1, 2, and 3 days, and then every other day until the end of re-epithelialization after surgery. Complete epithelial healing was verified with fluorescein staining examination after removal of BCLs ...

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    8. Visualisation of contrast-enhanced intraoperative optical coherence tomography with indocyanine green

      Visualisation of contrast-enhanced intraoperative optical coherence tomography with indocyanine green

      Optical coherence tomography (OCT)-based visualisation of ophthalmic anatomy has transformed the clinical practice of ophthalmology. The translation of OCT into the surgical theatre is currently being actively researched and may provide a paradigm shift in surgical practice. Enhanced visualisation of tissues and tissue planes may provide further iterative improvement in surgeon feedback. Contrast-enhanced intraoperative OCT ( i OCT) has been previously described with triamcinolone. In this report, we describe the OCT features and contrast enhancement noted with indocyanine green using i OCT in human subjects as well as an ex vivo analysis in porcine eyes.

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    9. Detection of early changes in caries lesion using QLF-D and OCT

      Detection of early changes in caries lesion using QLF-D and OCT

      Objectives We aimed to compare the differences in caries lesion changes when measured by QLF-D as fluorescence loss and by SS-OCT as lesion depth with respect to demineralized time, during formation of artificial early caries lesion. We also demonstrated that QLF-D and SS-OCT can be used effectively in monitoring the longitudinal progression of simulated caries lesions. Methods Ten bovine incisors were sectioned (5×4 mm) and embedded in epoxy resin. An acid-resistant nail varnish was applied to a part of the tooth surfaces to protect sound enamel (2×4 mm). To generate lesions, each specimen was immersed in 40 ml ...

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    10. Relationship Between Presence of Foveal Bulge in Optical Coherence Tomographic Images and Visual Acuity After Rhegmatogenous Retinal Detachment Repair

      Relationship Between Presence of Foveal Bulge in Optical Coherence Tomographic Images and Visual Acuity After Rhegmatogenous Retinal Detachment Repair

      Purpose: To determine whether a significant correlation exists between the presence of a bulge in the photoreceptor inner segment/outer segment line and the best-corrected visual acuity in eyes after successful rhegmatogenous retinal detachment (RRD) repair. Methods: Patients who had undergone successful RRD repair and had an intact inner segment/outer segment line at the central fovea in the spectral-domain optical coherence tomographic images were retrospectively studied. Thirty-five eyes of 35 patients were evaluated, and the eyes were classified preoperatively into those with macula-on RRD (n = 14) and those with macula-off RRD (n = 21). Examination of the spectral-domain optical coherence ...

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    11. Constructing 3D models of the pediatric upper airway from long range optical coherence tomography image

      Constructing 3D models of the pediatric upper airway from long range optical coherence tomography image

      Long-range optical coherence tomography has been developed to image the upper airway, obtaining high resolution, cross-sectional images of the hollow structure. The information obtained from the anatomical structure of the airway is important to objectively identify regions of airway obstruction. This paper describes a technique to create 3D reconstructions of the upper airway from LR-OCT images. Herein we outline the necessary steps to generate these 3D models, including image processing techniques, manual tissue segmentation in Mimics, anatomical curvature bending, and the final STL model rendition. These 3D models were used to qualitatively analyze structural changes before and after surgical interventions ...

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    12. Imaging of Naive Myopic Choroidal Neovascularization by Spectral-Domain Optical Coherence Tomography

      Imaging of Naive Myopic Choroidal Neovascularization by Spectral-Domain Optical Coherence Tomography

      Purpose: To assess the tomographic features of myopic choroidal neovascularization by spectral-domain optical coherence tomography. Methods: We consecutively reviewed the charts of patients with pathologic myopia, recent visual acuity deterioration and active macular neovascularization. Specific tomographic changes were studied in 25 eyes by two authors independently. Results: The mean age of patients eligible for the study was 63.4 (±18.2) years. Main tomographic outcomes were the hyperreflectivity of the lesion in 88% of cases (95% CI 0.74-1.02), absence of the external limiting membrane in 88% (95% CI 0.84-1.02), and retinal thickening in 83% (95% CI ...

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      Mentions: Luisa Pierro
    13. Iowa City VA Received a 2014 NIH Grant for Glaucoma Assessment using a Multimodality Image Analysis Approach

      Iowa City VA Received a 2014 NIH Grant for Glaucoma Assessment using a Multimodality Image Analysis Approach

      Iowa City VA Received a 2014 NIH Grant for Glaucoma Assessment using a Multimodality Image Analysis Approach. The principle investigator is Mona Garvin. The program began in 2012 and ends in 2015. Below is a summary of the proposed work. This Career Development Award-2 (CDA-2) is for supporting an early-career engineering faculty member for three years. It will provide the means to train a young researcher currently possessing broad image analysis experience and narrowly focused expertise in one ophthalmic imaging modality (optical coherence tomography, OCT) in a multitude of ophthalmic modalities and clinical areas, with a special focus on glaucoma ...

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    14. Wavefront Error Correction with Adaptive Optics in Diabetic Retinopathy

      Wavefront Error Correction with Adaptive Optics in Diabetic Retinopathy

      Purpose: To determine the effects of diabetic retinopathy (DR), increased foveal thickness (FT), and adaptive optics (AO) on wavefront aberrations and Shack-Hartmann (SH) image quality. Methods: Shack-Hartmann aberrometry and wavefront error correction were performed with a bench-top AO retinal imaging system in 10 healthy control and 19 DR subjects. Spectral domain optical coherence tomography was performed and central FT was measured. Based on the FT data in the control group, subjects in the DR group were categorized into two subgroups: those with normal FT and those with increased FT. Shack-Hartmann image quality was assessed based on spot areas, and high-order ...

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    15. Modern non-invasive diagnostic techniques in the detection of early cutaneous melanoma

      Modern non-invasive diagnostic techniques in the detection of early cutaneous melanoma

      Over the past few years melanoma has grown into a disease of socio-economic importance due to the increasing incidence and persistently high mortality rates. Melanoma is a malignant tumor with a high tendency to metastasize. Therefore, an extremely important part of the therapeutic process is to identify the disease at an early stage: in situ or stage I. Many tools for early diagnosis of melanoma are available today, including dermoscopy, videodermoscopy and in vivo reflectance confocal microscopy. Other methods such as high frequency ultrasound, optical coherence tomography and electrical impedance spectroscopy may serve as additional diagnostic aids. Modern imaging techniques ...

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    16. See all articles
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    1. (2 articles) Massachusetts Eye and Ear Infirmary
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  4. OCT Companies in the News

    1. (5 articles) Carl Zeiss Meditec
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    5. (2 articles) Bioptigen
    6. (1 articles) NinePoint Medical
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    8. (1 articles) Heidelberg Engineering
  5. OCT Products in the News

    1. (6 articles) Zeiss Cirrus HD-OCT
    2. (2 articles) Heidelberg Spectralis
    3. (1 articles) Optopol SOCT Copernicus
    4. (1 articles) Zeiss Stratus OCT
    5. (1 articles) Optovue iVue
    6. (1 articles) Tomey SS-1000 CASIA
    7. (1 articles) Topcon 3D OCT-2000
    8. (1 articles) NinePoint Nvision VLE Imaging System
    9. (1 articles) OptoMedical Technologies GmbH
  6. Picture Gallery

    New Endoscopic Technology Helps Diagnose Esophageal Cancer Quickly Bioptigen Unveils the Envisu IntraSurgical OCT System for Real-time Imaging During Ophthalmic Surgery Two Postdoctoral Positions in Optical imaging at Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA Swept-source OCT and glaucoma Intra-operative OCT devices for ophthalmic use: an overview Measurement of wavefront aberrations and lens deformation in the accommodated eye with optical coherence tomography-equipped wavefront system Virtual reality simulator for vitreoretinal surgery using integrated OCT data Assessment of early occlusal caries pre- and post- sealant application—An imaging approach Optical frequency domain imaging in patients with Barrett's neoplasia: an ex vivo case study with correlated endoscopic and histology views Postdoctoral Associate Position in Biophotonics at Stanford University Expanding OCT: Quanitifying the Cornea’s Optical Performance Postdoctoral Research Fellowships in Optical Coherence Tomography at Wellman Center for Photomedicine Massachusetts General Hospital
  7. Recent Quotes

    1. The I-POC program supports University innovations by bridging the gap between research and business, with a goal of making important technologies visible to the marketplace.
      By Lesley Millar-Nicholson
    2. This advance brings surgeons one step closer to realizing the full value of intraoperative OCT...This is the first OCT system offering fully independent focus and zoom control for optimizing images from the cornea to the retina.
      By Eric L. Buckland
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      By Sonia H. Yoo
    4. This advance brings surgeons one step closer to realizing the full value of intraoperative OCT
      By Eric L. Buckland
    5. The newest swept-source OCT has the advantage that the light source frequency sweep range and repetition rate can be adjusted to tailor the resolution, imaging range, and axial scan repetition rate for the specific imaging application.
      By James G. Fujimoto
    6. The light source emits different frequencies sequentially and is acquired at a very rapid speed. Also, the average wavelength is longer than SD-OCT. The premise is that you get deeper penetration into the tissue without the shadowing artifacts from overlying blood vessels like you do with SD-OCT.
      By Lucy Q. Shen
    7. This latest innovation from Bioptigen enables faster alignment, targeted explorations, and brilliant visualizations, while simultaneously viewing both OCT and color fundus images in real time...We expect this capability will be impactful not only for mouse and rat research, but also for handheld, dual-modality imaging of larger animals including cats, dogs, rabbits, and non-human primates," Buckland added. Bioptigen has begun producing and shipping the new multimodality systems from the company's North Carolina operations center, and will showcase the product at ARVO 2014 in Orlando, May 4-8.
      By Eric L. Buckland
    8. Currently available imaging equipment such as computer tomography or magnetic resonance tomography does not help us to analyse processes at the cell level like vascular deposits
      By Georg Rose
    9. It was a difficult decision but after numerous attempts by many dedicated people our ability to turn Imalux into an on-gong business was just not going to happen. The decision to cease operations is closely related to the significant financing challenges faced by early stage medical device companies in general and imaging companies specifically. It is unfortunate we closed the business but both current and past members of our team can be proud of all that was accomplished in trying to bring a new imaging technology to market. At some point there is little doubt our pioneering technology will be clinically adopted on a large scale in medicine. We thank our customers, investors and partners for their support and assistance over the years.
      By James M. Fulton
    10. We are pleased to have this clearance, and confident the results reflect the quality of our diagnostic tools in imaging that assist doctors in diagnosing ocular diseases
      By Motoki Ozawa